The present invention relates generally to tone generation apparatus and methods, and more particularly to an improved tone generation apparatus and method which are suitable for use in attaining or simulating, by means of an electronic musical instrument, tones that are generated by manipulation of a damper pedal on a natural or acoustic piano.
As well known, when any one of keys is depressed on a natural or acoustic piano, the pivoting movement of the depressed key rotates a wippen about a capstan so that a hammer is caused to strike one or more strings (hereinafter also called a xe2x80x9cstring setxe2x80x9d) associated with the depressed key and then immediately rebound from the string set via an escapement mechanism. In the meantime, a damper of the depressed key moves apart from the string set, and thus the string set is allowed to vibrate freely at a tone pitch corresponding to the depressed key in such a manner that the vibration is transmitted by way of a bridge to a soundboard for audible production or sounding of the tone. Once the depressed key is released, the damper is brought back into contact with the string set to terminate the vibration of the string set.
When a damper pedal of the piano is depressed with a player""s foot, the dampers of the individual keys are collectively moved apart from the string sets of all the keys, and thus all these string sets are allowed to freely vibrate together. If, in this damper-pedal-depressed state, there is any string set vibrating due to key depression of the player, the vibrating string set will excite vibration of one or more other string sets, which would bring about a resonant tone so that a piano tone with resonance is generated as a whole. Such a resonant tone constitutes a tone component peculiar to the piano.
To attain such a resonant tone electronically, i.e. by means of an electronic musical instrument, it is, in general, only necessary that a resonant tone component be added to a normal depressed-key tone in accordance with a pitch and tone volume level of the normal depressed-key tone, operating state of the damper pedal, etc. Techniques for electronically producing such a resonant tone are known, for example, from U.S. Pat. No. Re. 35813 and Japanese Patent Laid-open Publication No. SHO-60-91393. Manner of variation of the resonant tone component produced in the natural piano, however, would dynamically change depending on relative timing between the key operation and the damper pedal operation, depressed amount of the damper pedal, etc. For this reason, tones faithfully approximating acoustic piano tones can not be attained electronically, by merely starting generation of a resonant tone in response to depression of the damper pedal and controlling the tone volume level of the resonant tone in accordance with the depressed amount of the damper pedal. For example, in U.S. Pat. No. Re. 35813, there is disclosed a technique for imparting a resonant tone in response to activation or depression of the damper pedal. However, this disclosed technique is arranged to only terminate the resonant tone in response to deactivation or release of the damper pedal and thus can not provide appropriate dynamic control of the generated tone.
In view of the foregoing, it is a primary object of the present invention to provide an electronic tone generation apparatus, such as an electronic musical instrument, and electronic tone generation method which can appropriately simulate a damper pedal effect.
It is another object of the present invention to provide an tone generation apparatus and method which can dynamically control generation and characteristics of an additional tone, such as a resonant tone, related to a normal depressed-key tone on the basis of timing of the key depression and operation timing of an auxiliary performance operator and an operated amount of the auxiliary performance operator.
It is still another object of the present invention to provide a technique for electronically attaining a tone faithfully approximating an acoustic piano tone, by simulating tone components, such as a damper-pedal-excited additional tone and damper-pedal-off additional tone, with a hardware setup of a relatively small scale and relatively small amount of information processing.
To accomplish the above-mentioned object, the present invention provides a tone generation apparatus which comprises: a performance operation device adapted to instruct generation of a tone; an auxiliary performance operator having at least two operation states: an ON operation state; and an OFF operation state; and a processor device coupled with the performance operation device and the auxiliary performance operator. The processor device is adapted to: generate a normal tone in accordance with an instruction given by the performance operation device; and start, when the auxiliary performance operator is operated while the normal tone is being generated, generation of additional tones that correspond to the at least two operation states of the auxiliary performance operator and are related to the normal tone being generated.
The tone generation apparatus of the present invention thus arranged can generate or sound additional tones, related to the currently-generated normal or main tone, which correspond to the ON operation state and OFF operation state of the auxiliary performance operator and have respective unique characteristics.
In a preferred implementation, the processor device is further adapted to determine a tone volume level, at the beginning of generation, of the additional tone in accordance with an elapsed time from the beginning of generation of the normal tone to the beginning of generation of the additional tone. With this arrangement, the additional tone related to the currently-generated normal tone can be controlled to have a tone volume level corresponding to a sounding state of the normal tone.
As an example, the processor device may be further adapted to determine a volume level, at the beginning of generation, of the additional tone, in accordance with a tone volume level of the normal tone at beginning of generation of the additional tone. With this arrangement, the additional tone related to the currently-generated normal tone can be controlled to have a tone volume level corresponding to a sounding state of the normal tone.
In another preferred implementation, the auxiliary performance operator is capable of generating information indicative of an operated amount thereof including an intermediate operation value between the ON operation state and the OFF operation state. In this case, the processor device is further adapted to control at least one of decay rates of the normal tone and the additional tone in accordance with the information indicative of the operated amount generated by the auxiliary performance operator. With this arrangement, the tone volume levels of the currently-generated normal tone and related additional tone can be varied in accordance with an operated amount of the auxiliary performance operator; for example, the tone volume levels of the currently-generated normal tone and related additional tone can be controlled to not vary over time in such a manner that they can have characteristics similar to those of decay tones generated by a natural or acoustic musical instrument.
In another preferred embodiment, the processor device is adapted to additionally generate a returning tone related to the normal tone being generated, provided that the normal tone is being generated when the auxiliary performance operator has returned from the ON operation state to the OFF operation state. This arrangement permits appropriate simulation of a tone variation that would occur as the auxiliary performance operator, controlling the generation or sounding of the additional tone related to the normal tone, is deactivated or brought to the OFF operation state.
According to another aspect of the present invention, there is provided a tone generation apparatus which comprises: a performance operation device adapted to instruct generation of a tone; an auxiliary performance operator having at least two operation states: an ON operation state; and an OFF operation state; and a processor device coupled with the performance operation device and the auxiliary performance operator, the processor device being adapted to: generate a normal tone in accordance with an instruction given by the performance operation device; and start, when the auxiliary performance operator is brought to the OFF operation state while the normal tone is being generated, generation of an additional tone that is related to the normal tone being generated. This inventive arrangement permits impartment of a special additional tone (e.g., returning tone) when the auxiliary performance operator, such as a pedal, is deactivated or brought to the OFF operation state, thereby effectively contributing to appropriate dynamic tone control.
The present invention may be constructed and implemented not only as the apparatus invention as discussed above but also as a method invention. Also, the present invention may be arranged and implemented as a software program for execution by a processor such as a computer or DSP, as well as a storage medium storing such a program. Further, the processor used in the present invention may comprise a dedicated processor with dedicated logic built in hardware, rather than a computer or other general-purpose type processor capable of running a desired software program.
While the embodiments described herein represent the preferred form of the present invention, it is to be understood that various modifications will occur to those skilled in the art without departing from the spirit of the invention. The scope of the present invention is therefore to be determined solely by the appended claims.